Pattern 2: It is also possible to express the indirect object with the preposition à and the unconnected personal pronouns. This is always used, if the accusative object is any other than le, la, les (= me, te, nous and vous). This is quite logical, because the dative/indirect and accusative/direct object are identical. Here, we would have a risk of mix up, therefore the preposition is used. The pronominal adverb is then between the accusative/direct and the dative/indirect object.
Dative / indirect object:
preposition à + unconnected personal pronouns) moi, toi, lui, nous, vous, eux